Lines in thick engraving

[Andrew Barney]

Hello everyone,
I am new to the engravers world. Picked up a used ULS25E 25w engraver. I noticed when I engrave thick areas I get horizontal lines in what is being engraved. This happens on all of the materials I have tried this on and there does seem to be a pattern. The laser tube was replaced a little over 1.5 years ago and has low hours on it from what the previous owner mentioned.

The picture below was engraved into Rowmark at 30% power, 100% speed, 500 PPI. I cut it out whwen done with no issues at 75/2.0/500. Everything I have vector cut has given me no issue. Smaller letters do not show this type of effect.

Any help or suggestions is appreciated.

Thank you!

Andrew

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[Mike Null]

Only a guess but that seems to be a leak. Have you contacted ULS tech support?

[Andrew Barney]

Mike,

I actually called them today. Very helpful folks for a 12 year old machine! I was impressed.

They had me adjust the tickle settings, which seems to not be fixing it. He thought it may be a leaky tube...

When you said leak, I thought, good... a HV leak or some such thing. Sadly you meant leaky tube. Lame.

Anyways, I sent them some photos of the trouble and am still messing with the tickle settings.

Thanks,

Andrew

[Mike Null]

Andrew

Sorry I wasn't more specific. I had a leak problem on an old Epilog I used and we did not have to replace the tube. It was 12 years ago and I've forgotten what we did but Epilog tech support walked us through it.

It's possible that this is a communications issue. I would replace your printer cable if you have a spare on hand. At least disconnect, clean and reconnect it. Reinstall your driver (ask ULS for the latest for your machine). Maybe reinstall the printer/port- I imagine that uses parallel cables.

[Andrew Barney]

Mike,

Thanks for the tips, I will swap cables and see how it goes. My hope is at fault for the leak thing, not on you at all. I will talk to ULS again in the AM and see about the drivers.

The reason I was so hopeful (and thought I may be ok) was the tube was replaced about 1.5 years ago... this thing was not in production or anything, so I am sort of shocked that it could be bad.

I will let you know how it goes, and thank you again.

Andrew

[Mike Null]

The engraving you show would not indicate a bad tube in my opinion.

Is it the photo or did you do a gold colorfill on the name tag?

Do you get the same effect when you change fonts or is it only this font?

[Andrew Barney]

I typed what I wanted and than inverted the colors... rastered the background out and the gold is what was left. I used the settings that the previous owner had recorded for that material...

I get the same problem is I engrave a 1" x 1" black square, it gets lines. They change when I mess with the tickle settings, they just don't go away ever.

Andrew

[Mike Mackenzie]

Andrew,

This looks to me like one of two things. Power supply fluctuating or motion system (bearings , belts, Idler, Motor). Try putting a volt meter onto the power supply and run the system watch for drops in voltage as it runs.

Try rotating the graphic and see if you get the same bands also move it to a different spot on the table to see if it changes.

[Andrew Barney]

I will give it a shot and let you know how it goes. Everything moves freely, but a simple test is easy.

ULS tech support thinks it is the laser :( so I am hoping it is something else. I will let you know how it goes.

Thanks,

Andrew

[Andrew Barney]

Hey Mike,

The 28v supply runs sold at 28.26 volts with no change during operation. I did not test anything on the driver board, but can if you like or think it would help.

I placed several squares in various location on my sheet and rastered them, they all have some light banding in them. I also rotated several and all bands still run horizontally.

Thanks again.

Andrew

[Mike Null]

Andrew

Have you varied the dpi setting? If so, what was the result?

If you send the job with a speed setting of 10 does it engrave the banded area? Just grasping at straws to see if you really have a leak. There's probably an easier way.

[Tim Eddings]

I typed what I wanted and than inverted the colors... rastered the background out and the gold is what was left.
I may be way off base here, but are you using Rowmak gold cap with black core? If that is the case then it would seem that it would be a lot more economical to use a black cap with gold core, then you are only lasering the letters, not the whole back ground.
Just a thought.
Tim

[Mike Mackenzie]

Andrew,

Run the power supply test using 100 power and 10 speed just let it run on the table for about 1/2 hour then see if the power supply is stable.

I do not know if you know how to tension the X belt but I would play with the tensioning of the X belt to see if the bands get better or worse. Also try doing some tests with different materials.

It does sound like it could be the laser tube however I have seen belt tension and or X Motor cause this type of problem. You could also try cleaning the drive gear use a toothpick and clean the teeth on the gear. You do not have to remove anything to do this.

[Ross Moshinsky]

To me it just looks like the plastic melting at different rates due to the amount of text on the line. I'd be curious to see what that looks like on acrylic or coated metal.

[Andrew Barney]

Hey everyone,

I wanted to follow up on this post, it has been a while! I appreciate everyones input and your help Mike.

Here is how this was fixed:
1) The RCA cable to the tube had a bad end on the board side of the wire. I replaced the end.
2) I tore everything apart... I mean EVERYTHING and cleaned it. Every tiny little bit. It was filthy in a surprising way for looking basically clean on the outside.
3) I realigned all of the mirrors and cleaned all of the mirrors and lenses.
4) I bled, I figured this was worth mentioning as possibly a needed step to make this thing work right.
Public service message: Don't put your finger in the high speed cooling fans. They are sharp. Unless you think bleeding will help the problem with your laser.
5) Messed with speed, power and DPI and found the settings I used originally were ok. Yes I was using the laser a lot to make the plate the way I did... but it was the look I was going for on this specific piece. In the future, I will do a reverese of this.

Problem is gone and all behaves as it should.

Thank you all again!

Andrew

[Emma austin]

Oh wow so all that black in the photo has been rastered away? Why are you doing it that way?
I don't think you will ever get a smooth black surface like that. If you had black top rowmark with gold core, you would o my be rastering the letters and wouldn't have that effect?
Sorry if I am totally off track though?